Question

The most abundant element found in the earth's crust is :

• A. O
• B. Cl
• C. Si
• D. S

Hint:

Remember the top two most abundant elements in the Earth's crust (by mass): 1. {O}xygen (\(\sim 47%\)) 2. {Si}licon (\(\sim 28%\)) These two elements are the main components of most rocks and minerals (silicates). (Mnemonic: "{O}h, {Si}lly {Al}fie..." for Oxygen, Silicon, Aluminum, Iron).

Answer 1

The Correct Option is A

Concept: The Earth's crust is composed of various elements, but some are significantly more abundant than others by mass. Step 1: Major Elements in Earth's Crust by Approximate Percentage Mass % Option (A) Oxygen (O): About 46.6% % Option (B) Silicon (Si): About 27.7% % Option (C) Aluminum (Al): About 8.1% % Option (D) Iron (Fe): About 5.0% % Option (E) Calcium (Ca): About 3.6% % Option (F) Sodium (Na): About 2.8% % Option (G) Potassium (K): About 2.6% % Option (H) Magnesium (Mg): About 2.1% All other elements make up the remaining percentage (less than 2%). Step 2: Identifying the most abundant element From the list, Oxygen (O) is the most abundant element in the Earth's crust by mass. It is primarily found in combined form in silicate minerals (like quartz, feldspar, mica), oxides, carbonates, sulfates, etc. Step 3: Evaluating the options % Option (I) (1) O (Oxygen): \(\sim 46.6%\) - Most abundant. % Option (J) (2) Cl (Chlorine): Much less abundant than oxygen or silicon. Found in minerals like halite (NaCl). % Option (K) (3) Si (Silicon): \(\sim 27.7%\) - Second most abundant. % Option (L) (4) S (Sulfur): Less abundant than oxygen or silicon. Found in sulfide and sulfate minerals. Therefore, Oxygen is the most abundant element in the Earth's crust.